A qualitative analysis of pediatric otolaryngology fellowship websites.

OBJECTIVE: To evaluate the availability and breadth of information provided by program-created pediatric otolaryngology fellowship websites as well as the American Society of Pediatric Otolaryngology (ASPO) program directory. METHODS: Program-created pediatric otolaryngology fellowship websites and the ASPO directory were evaluated for 16 key criteria deemed to be relevant to fellowship applicants. RESULTS: All 36 ACGME-accredited pediatric otolaryngology fellowship programs had websites that were readily available by Google search, and the ASPO program directory contained direct links to 17 (47.2 %) program-created websites. On average, program-created websites fulfilled 6.9 (43.1 %, range 1-11) and the ASPO directory fulfilled 6.9 (43.1 %, range 3-11) of the 16 key criteria. When utilizing both resources, the average increased to 8.3 (51.2 %) - criteria included program description (94.4 %), location description (30.4 %), fellowship director contact information (94.4 %), program coordinator contact information (72.2 %), teaching responsibilities (68.6 %), call responsibilities/schedule (41.7 %), operative volume (80 %), breadth of surgical exposure (94.4 %), research opportunities (72.2 %), research expectations (63.9 %), current fellow(s) (42.9 %), post-fellowship placement (28.6 %), fellow clinic (28.6 %), medical missions/outreach (20 %), and resident coverage (36.1 %). CONCLUSION: Pediatric otolaryngology fellowship websites as well as program-specific data sheets from ASPO lack many key criteria that would otherwise be valuable to applicants. Inclusion of these criteria could help applicants make a more well-informed decision when applying into pediatric otolaryngology fellowship.

A nomogram to predict long-term facial nerve function after vestibular schwannoma resection: a contemporary multi-institutional study.

OBJECTIVE: The objective of this study was to develop a nomogram to predict long-term facial nerve (FN) function after vestibular schwannoma (VS) resection. METHODS: A retrospective cohort study of two tertiary academic skull base referral centers was performed. Consecutive adults > 18 years of age with sporadic unilateral VS who underwent resection between September 2016 and May 2021 were included. FN function in the immediate postoperative period and at the most recent evaluation was measured. RESULTS: A total of 306 patients (mean age 49 years, 63% female) were included, with a mean follow-up of 18 months. The mean maximum tumor diameter was 19 mm (range 1-50 mm), and 80 (26.1%) tumors were > 25 mm. Overall, 85% of patients showed good immediate postoperative FN function (House-Brackmann [HB] grade I or II) and 89% maintained good FN function at > 12 months of follow-up. An intraoperative FN electromyographic (EMG) response ≥ 100 µV to 0.05 mA of stimulation (OR 18.6, p < 0.001) was the strongest predictor of good HB grade in the immediate postoperative period. EMG response ≥ 100 µV (OR 5.70, p < 0.001), tumor size ≤ 25 mm (OR 3.09, p < 0.05), and better immediate postoperative HB grade (OR 1.48, p = 0.005) predicted good long-term FN function on multivariable analysis. A point-of-care nomogram based on these data predicted long-term FN function with a sensitivity of 89% and specificity of 69%. CONCLUSIONS: Better immediate postoperative HB grade, intraoperative FN EMG response ≥ 100 µV, and tumor size ≤ 25 mm strongly predicted good long-term FN function after VS resection. A point-of-care nomogram based on these variables could serve as a useful tool for postoperative counseling and prognosis of long-term FN recovery.

The role of induction chemotherapy for orbital invasion in sinonasal malignancies: A systematic review.

BACKGROUND: Sinonasal malignancies (SNMs) frequently present with orbital invasion. Orbital exenteration (OE) can lead to significant morbidity. Induction chemotherapy (IC) is a promising treatment alternative that may allow for orbit preserving (OP) treatments without compromising patient survival. This systematic review was conducted to synthesize the published data on SNM patients with orbital invasion who underwent IC, including tumor response, orbital outcomes, and survival. METHODS: The study protocol was designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Databases Embase, Cochrane, Medline, and Scopus, from inception to July 17, 2023, were searched. RESULTS: Nineteen studies were included, encompassing 305 SNM patients with orbital invasion treated with IC. Fourteen studies reported an overall IC response rate (positive response defined as complete or partial tumor volume reduction) of 77.2%. Among included studies, OE rates after IC ranged from 0 to 40%. Three studies reported a high rate of posttreatment functional orbital preservation (89.8-96.0%). Five studies specifically reported that 62.5% (60 out of 96) of patients were downgraded from planned OE to OP treatment following IC. Three studies reported a significant overall survival (OS) improvement in IC responders versus IC nonresponders. Following IC, 5-year OS ranged from 44.2 to 55.5%. Patients with olfactory neuroblastoma demonstrated the highest IC response rate and lowest OE rate (100 and 0%, respectively) versus those with sinonasal undifferentiated carcinomas (68.4 and 0%) or squamous cell carcinomas (76.7 and 16%). CONCLUSIONS: For select patients, IC may allow for OP in locally advanced SNMs with orbital involvement.

Comparison of Postoperative Outcomes in Cystic Versus Solid Vestibular Schwannoma in a Multi-institutional Cohort.

OBJECTIVE: Cystic vestibular schwannomas (cVSs) have more variable and less favorable clinical outcomes after microsurgical resection compared with solid VS (sVS). This study compares the preoperative presentation and postoperative outcomes between cVS and sVS. STUDY DESIGN: Retrospective cohort study. SETTING: Two tertiary skull base referral centers. METHODS: Consecutive adult patients who underwent VS resection from 2016 to 2021 were included. Univariate and multivariate analyses compared differences in baseline symptoms and postoperative outcomes between cVS and sVS. RESULTS: There were a total of 315 patients (64% female; mean age, 54 yrs) and 46 (15%) were cystic. cVS were significantly larger than sVS (maximum diameter, 28 vs. 18 mm, p < 0.001) and had higher rates of dysphagia and dysphonia preoperatively (p < 0.02). cVSs were more likely to undergo translabyrinthine resection (76 vs. 50%, p = 0.001) and have a higher rate of subtotal resection (STR) compared with sVS (30 vs. 13%, p = 0.003). At latest follow-up, fewer cVS achieved good facial nerve (FN) outcome (House-Brackmann [HB] I/II) (80 vs. 90%, p = 0.048). Subanalysis of cVS and sVS matched in tumor size, and surgical approach did not show differences in the rate of STR or FN outcomes (HB I/II, 82 vs. 78%, p = 0.79). CONCLUSION: In this large multi-institutional series, cVSs represent a distinct entity and are characterized by larger tumor size and higher incidence of atypical symptoms. Although cVSs were more likely to undergo STR and portend worse FN outcomes than sVSs, this may be due to their larger tumor size rather than the presence of the cystic component.

Hypoglossal Nerve Stimulation Therapy Outcomes in Apnea- Versus Hypopnea-Predominant Patients.

OBJECTIVES: The influence of apnea- and hypopnea-predominance on hypoglossal nerve stimulation therapy outcomes (HGNS) is still poorly defined. We assessed the significance of apnea- and hypopnea-predominance in HGNS outcomes. STUDY DESIGN: Case series with chart review. SETTING: Single-institution tertiary care center. METHODS: A total of 216 subjects were included, all of which had undergone drug-induced sleep endoscopy (DISE) and HGNS implantation. Demographic and polysomnographic data were collected. The 4% apnea-hypopnea criteria were used to calculate apnea-hypopnea index (AHI). Central apneas were omitted. Univariate logistic and linear regression were used to study the association between these data and apnea-predominance and hypopnea-predominance. Kruskal-Wallis rank sum test was used to compare medians between groups for DISE collapse patterns. RESULTS: Sixty-three patients were apnea-predominant, and 153 patients were hypopnea-predominant. These 2 groups were similar demographically (p > .20). There was no significant difference in HGNS outcomes between the groups assessed using Sher20 criteria at the 1-year mark using all-night, single-setting polysomnography or home sleep studies. Apnea index (AI)/AHI and reduction in AHI from preoperative to titration were significantly associated (p = .046). The median preoperative hypopnea index was significantly lower (p = .033) in subjects with no oropharyngeal collapse than patients with partial or complete oropharyngeal collapse. There were no significant relationships between AI/AHI and the different degrees of collapse at the velopharynx, oropharynx, tongue base, or epiglottis. CONCLUSIONS: In line with CPAP, tonsillectomy, and mandibular advancement therapy studies, we found there was largely no significant difference in DISE anatomy or in HGNS treatment outcomes between apnea- and hypopnea-predominant individuals.

Outcomes After Transcutaneous Bone-Conduction Implantation in Adults and Children.

OBJECTIVE: To evaluate clinical and audiometric outcomes of adult and pediatric patients implanted with a semi-implantable transcutaneous active bone-conduction implant. STUDY DESIGN: Retrospective chart review. SETTING: Two tertiary referral centers. PATIENTS: Subjects implanted with the semi-implantable transcutaneous active bone-conduction implant called BoneBridge. INTERVENTION: Implantation of the BoneBridge and audiometric evaluations. MAIN OUTCOME MEASURES: Audiometric, clinical, and surgical outcomes as well as complications. RESULTS: Forty-two adults and 20 children were implanted for conductive or mixed hearing loss as well as single-sided deafness. Implantation significantly improved mean air-conduction pure-tone average from 72.8 ± 22.3 to 35 ± 9 dB in adults and from 65.7 ± 24.3 to 19.6 ± 8.2 dB in children (both p < 0.001). Word recognition score improved from 63.7 ± 38.8% to 85.6 ± 10.6% in adults and 57.8 ± 38% to 89.3 ± 10.1% in children (both p < 0.05). The rate of revision surgery was 11.3%, with four patients (6.5%) undergoing removal for device-related complications, two (3.2%) for complications associated with implantation, and one (1.6%) for device failure secondary to external trauma. CONCLUSIONS: In a large retrospective series consisting of both pediatric and adult patients, implantation with a transcutaneous active bone-conduction implant was found to be a reliable aural rehabilitation option for a variety of hearing loss etiologies.

Therapeutic targeting of prenatal pontine ID1 signaling in diffuse midline glioma.

BACKGROUND: Diffuse midline gliomas (DMG) are highly invasive brain tumors with rare survival beyond two years past diagnosis and limited understanding of the mechanism behind tumor invasion. Previous reports demonstrate upregulation of the protein ID1 with H3K27M and ACVR1 mutations in DMG, but this has not been confirmed in human tumors or therapeutically targeted. METHODS: Whole exome, RNA, and ChIP-sequencing was performed on the ID1 locus in DMG tissue. Scratch-assay migration and transwell invasion assays of cultured cells were performed following shRNA-mediated ID1-knockdown. In vitro and in vivo genetic and pharmacologic [cannabidiol (CBD)] inhibition of ID1 on DMG tumor growth was assessed. Patient-reported CBD dosing information was collected. RESULTS: Increased ID1 expression in human DMG and in utero electroporation (IUE) murine tumors is associated with H3K27M mutation and brainstem location. ChIP-sequencing indicates ID1 regulatory regions are epigenetically active in human H3K27M-DMG tumors and prenatal pontine cells. Higher ID1-expressing astrocyte-like DMG cells share a transcriptional program with oligo/astrocyte-precursor cells (OAPCs) from the developing human brain and demonstrate upregulation of the migration regulatory protein SPARCL1. Genetic and pharmacologic (CBD) suppression of ID1 decreases tumor cell invasion/migration and tumor growth in H3.3/H3.1K27M PPK-IUE and human DIPGXIIIP* in vivo models of pHGG. The effect of CBD on cell proliferation appears to be non-ID1 mediated. Finally, we collected patient-reported CBD treatment data, finding that a clinical trial to standardize dosing may be beneficial. CONCLUSIONS: H3K27M-mediated re-activation of ID1 in DMG results in a SPARCL1+ migratory transcriptional program that is therapeutically targetable with CBD.

Sentinel node mapping and biopsy in ectopic axillary breast cancer: A case report and review of the literature.

Sentinel lymph node mapping in patients with axillary breast carcinoma is technically challenging and poorly described in the literature. We report a patient with primary ectopic breast carcinoma of the axilla in whom concurrent peri-tumoral and intra-tumoral injection of radionuclide tracer allowed for identification and biopsy of sentinel lymph nodes.

Near-Peer Teaching in Conjunction with Flipped Classroom to Teach First-Year Medical Students Basic Surgical Skills.

Background: There is increasing evidence that students are completing medical school with insufficient surgical education. Near-peer tutoring and flipped classroom formatting may be used to enhance learning while simultaneously relieving faculty burden of teaching. Here, we qualitatively evaluate a 3-month course that integrates the use of near-peer teaching and flipped classroom formatting, with the goal of increasing first-year medical students' self-perceived confidence in performing basic sutures and knot-ties as well as interest in surgery. Methods: Twenty-one first-year medical students participated in a suturing and knot-tying course led by senior medical students. The course consisted of 2-h sessions held every 2 weeks for a total of five sessions. Students were sent publicly available videos prior to each session by which to learn the upcoming techniques and received live feedback from instructors during sessions. Questionnaires were completed pre-course and post-course. Results: Compared to pre-course ratings, post-course ratings of self-perceived confidence to perform various knot-ties and sutures all increased significantly (p < 0.05). All students stated that the course strengthened their desire to pursue a career in surgery. Student feedback of the course was overall positive. Conclusions: Near-peer teaching can be used in conjunction with flipped classroom to increase first-year medical students' self-perceived confidence in surgical suturing and knot-tying as well as interest in surgery. This curriculum may serve as an outline for student-led courses at other institutions.

Severe Thrombocytopenia Associated with Dengue Fever: An Evidence-Based Approach to Management of Thrombocytopenia.

Dengue is a mosquito-borne viral illness common in tropical and subtropical countries but very rare in the United States. Patients infected with dengue often present with thrombocytopenia. In the setting of dengue, platelet transfusions as a treatment for thrombocytopenia have no clear benefits in reduction of severe bleeding or improvement of the platelet count. Here, we present a case of a traveler infected with dengue virus and discuss the approach to treat thrombocytopenia.

Multi-institutional analysis of central nervous system germ cell tumors in patients with Down syndrome.

PURPOSE: Primary germ cell tumors (GCTs) are the most common central nervous system (CNS) neoplasm in patients with Down syndrome (DS). However, a standard of care has not been established due to paucity of data. METHODS: A retrospective multi-institutional analysis was conducted, in addition to a comprehensive review of the literature. RESULTS: Ten patients from six institutions (five USA, one Brazil) were identified, in addition to 31 patients in the literature from 1975 to 2021. Of the 41 total patients (mean age 9.9 years; 61% male), 16 (39%) had non-germinomatous germ cell tumors (NGGCTs), 16 (39%) had pure germinomas, and eight (19.5%) had teratomas. Basal ganglia was the most common tumor location (n = 13; 31.7%), followed by posterior fossa (n = 7; 17%). Nine patients (22%) experienced disease relapse or progression, of which four died from tumor progression (one germinoma, three teratomas). Sixteen patients (39%) experienced treatment-related complications, of which eight (50%) died (five germinomas, three NGGCTs). Of the germinoma patients, two died from chemotherapy-related sepsis, one from postsurgery cardiopulmonary failure, one from pneumonia, and one from moyamoya following radiation therapy (RT). Of the NGGCT patients, one died from chemotherapy-related sepsis, one from postsurgical infection, and one from pneumonia following surgery/chemotherapy/RT. Three-year overall survival was 66% for all histological types: 62% germinomas, 79% for NGGCTs, and 53% for teratomas. CONCLUSION: Patients with DS treated for CNS GCTs are at an increased risk of treatment-related adverse events. A different therapeutic approach may need to be considered to mitigate treatment-related complications and long-term neurocognitive sequelae.

ATRX loss in glioma results in dysregulation of cell-cycle phase transition and ATM inhibitor radio-sensitization.

ATRX, a chromatin remodeler protein, is recurrently mutated in H3F3A-mutant pediatric glioblastoma (GBM) and isocitrate dehydrogenase (IDH)-mutant grade 2/3 adult glioma. Previous work has shown that ATRX-deficient GBM cells show enhanced sensitivity to irradiation, but the etiology remains unclear. We find that ATRX binds the regulatory elements of cell-cycle phase transition genes in GBM cells, and there is a marked reduction in Checkpoint Kinase 1 (CHEK1) expression with ATRX loss, leading to the early release of G2/M entry after irradiation. ATRX-deficient cells exhibit enhanced activation of master cell-cycle regulator ATM with irradiation. Addition of the ATM inhibitor AZD0156 doubles median survival in mice intracranially implanted with ATRX-deficient GBM cells, which is not seen in ATRX-wild-type controls. This study demonstrates that ATRX-deficient high-grade gliomas (HGGs) display Chk1-mediated dysregulation of cell-cycle phase transitions, which opens a window for therapies targeting this phenotype.

Recurrent Wnt medulloblastoma treated with marrow-ablative chemotherapy and autologous hematopoietic progenitor cell rescue: a dual case report and review of the literature.

Wnt-activated medulloblastoma (MB) confers an excellent prognosis. However, specific treatment strategies for patients with relapsed Wnt-MB are unknown. We report two patients with recurrent beta-catenin nucleopositive Wnt-MB successfully treated by incorporating marrow-ablative chemotherapy and autologous hematopoietic progenitor cell rescue (HDCx/AuHPCR). We also present a review of the literature for previously reported cases of relapsed Wnt-MB. We propose that patients with recurrent Wnt-MB may be treated using a multi-disciplinary approach that includes HDCx/AuHPCR with or without re-irradiation.

Incidence of central line associated bloodstream infection following central venous catheter placement in the emergency department.

INTRODUCTION: Central line-associated bloodstream infections (CLABSI) are costly and can be lifethreatening. Many efforts have been taken to minimize the rates of infection, including sterile technique, pre-packaged sterile kits, site selection, and replacing infected or potentially infected lines. This study aims to identify the incidence of CLABSI following catheter placement in the ED, and to compare rates of CLABSI among ED and ICU placed catheters. METHODS: This retrospective chart review was conducted at a Level 1 Trauma Center. Eligibility criteria included patients who had CVC placed in the ED or ICU from January 1st, 2018, through July 31st, 2019 who were 18 years or older. RESULTS: Among 1810 patients with central lines, 1254 met eligibility criteria. There was no significant difference in infection rates when comparing lines placed in the ED (2.5 per 1000 catheter days, 95% confidence interval [CI] 0.8 to 5.8) compared to those placed in the ICU (4.6 per 1000 catheter days, 95% CI 3.0 to 6.8). The odds of CLABSI was not associated with age, sex, indication, site, location nor which type of health care professional (HCP) placed the line. CONCLUSIONS: In this study, the incidence of infection was no different between lines placed in the ED compared to the ICU.

Water Vapor Endometrial Ablation for Heavy Menstrual Bleeding: 36-Month Follow-Up of a Prospective, Multicenter Pivotal Clinical Trial.

STUDY OBJECTIVE: To report 36-month follow-up of a pivotal trial that evaluated the safety and effectiveness of the AEGEA Water Vapor System for the treatment of heavy menstrual bleeding (HMB) secondary to Abnormal Uterine Bleeding due to Endometrial disorders or Leiomyomata (AUB-E and AUB-L). METHODS: A prospective, multicenter, single-arm clinical trial at 14 sites in the US, Canada, Mexico, and the Netherlands. Inclusion criteria included a Pictorial Blood Loss Assessment (PBLAC, Higham) score ≥150 and allowed treatment of subjects with leiomyomata classified by the International Federation of Gynecology and Obstetrics (FIGO) Types 2-6 up to 4 cm in diameter, a uterine cavity up to 12 cm in length (uterine sound), Essure® contraceptive inserts and/or prior cesarean section. Follow-up assessments were conducted annually up to 36 months after endometrial ablation. The following outcomes were evaluated for 125/155 women: gynecological adverse events, qualitative assessment of menstrual flow, quality of life using the Menorrhagia Impact Questionnaire (MIQ), patient satisfaction, and medical or surgical reintervention for AUB. RESULTS: One hundred and fifty-five premenopausal women aged 30 to 50 years were enrolled from September 2014 through May 2015. Water vapor endometrial ablation was performed under varying anesthesia/sedation regimens in offices, surgical centers and operating rooms. There were 6 procedure-related adverse events that occurred between 12- and 36-month follow-up, 1 of which was deemed serious (hematometra managed successfully hysteroscopically). Seventy-two percent reported amenorrhea or light menstrual flow. The mean quality of life (MIQ) score improved from 14.7 at baseline to 6.4. Ninety-three percent reported "Satisfied" or "Very Satisfied." Post-ablation hysterectomy for any indication was performed in 6.5% of patients, and the total rate of re-intervention for bleeding was 7.1%. CONCLUSION: Outcomes 36-months after water vapor endometrial ablation for HMB are consistent with 12- and 24-month follow-up results in all subgroups evaluated. The AEGEA Water Vapor System increases the population of patients amenable to efficacious and acceptable treatment of Heavy Menstrual Bleeding (HMB) due to Abnormal Uterine Bleeding (AUB-E,-L). CinicalTrials.gov NCT01979861 registered November 8, 2013.

Correction to: Targeting and Therapeutic Monitoring of H3K27M-Mutant Glioma.

The original version of this review article unfortunately contained a mistake in the author group section.

Targeting and Therapeutic Monitoring of H3K27M-Mutant Glioma.

PURPOSE OF REVIEW: H3K27M is a frequent histone mutation within diffuse midline gliomas and is associated with a dismal prognosis, so much so that the 2016 CNS WHO classification system created a specific category of "Diffuse Midline Glioma, H3K27M-mutant". Here we outline the latest pre-clinical data and ongoing current clinical trials that target H3K27M, as well as explore diagnosis and treatment monitoring by serial liquid biopsy. RECENT FINDINGS: Multiple epigenetic compounds have demonstrated efficacy and on-target effects in pre-clinical models. The imipridone ONC201 and the IDO1 inhibitor indoximod have demonstrated early clinical activity against H3K27M-mutant gliomas. Liquid biopsy of cerebrospinal fluid has shown promise for clinical use in H3K27M-mutant tumors for diagnosis and monitoring treatment response. While H3K27M has elicited a widespread platform of pre-clinical therapies with promise, much progress still needs to be made to improve outcomes for diffuse midline glioma patients. We present current treatment and monitoring techniques as well as novel approaches in identifying and targeting H3K27M-mutant gliomas.

Post-Ablation Cavity Evaluation: A Prospective Multicenter Observational Clinical Study to Evaluate Hysteroscopic Access to the Uterine Cavity 4 Years after Water Vapor Endometrial Ablation for the Treatment of Heavy Menstrual Bleeding.

STUDY OBJECTIVE: Patients who have undergone endometrial ablation may present a diagnostic challenge when they subsequently develop vaginal bleeding, pelvic pain, or postmenopausal bleeding. Extensive scarring of the uterine cavity often precludes evaluation and/or conservative treatment. For further research on this topic, we performed hysteroscopic examination in study subjects a mean duration of 4 years after they had undergone water vapor endometrial ablation. DESIGN: Prospective, multicenter, observational clinical study. SETTING: Eight private practice or outpatient sites in the United States and Mexico. PATIENTS: Seventy subjects who had completed their 36-month follow-up in the AEGEA Pivotal Trial. INTERVENTIONS: Diagnostic hysteroscopy. MEASUREMENTS AND MAIN RESULTS: The subjects were screened for general health and infection and underwent diagnostic hysteroscopy. Menstrual bleeding status was recorded. The video of the hysteroscopic examination was analyzed by an independent reviewer, who assessed uterine cavity access and visualization of the cornua and tubal ostia as well as characterized adhesions on the basis of the criteria by March et al. An independent reviewer also subjectively assessed whether Pipelle endometrial biopsy or intrauterine device placement would be feasible. Uterine cavity access was achieved in 90% (63/70) of subjects. Among subjects with cavity access, the cornua and ostia were visualized in 79% (50/63) and adhesions were absent in 75% (47/63), with only 2 women having severe adhesions (3%, 2/63). Biopsy was projected to be feasible in 86% (62/70) and intrauterine device placement in 60% (42/70) of all subjects. The subjects' bleeding statuses were not correlated with uterine cavity access. The results were consistent for subjects with large uterine cavities and International Federation of Gynecologic and Obstetrics type II to VI myomas ≤4 cm. CONCLUSION: Water vapor endometrial ablation preserved an accessible uterine cavity and visualization of the ostia in most subjects, with minimal incidence of severe adhesions, a mean of 4 years after the ablation procedure.

Role of dopamine and selective dopamine receptor agonists on mouse ductus arteriosus tone and responsiveness.

BACKGROUND: Indomethacin treatment for patent ductus arteriosus (PDA) is associated with acute kidney injury (AKI). Fenoldopam, a dopamine (DA) DA1-like receptor agonist dilates the renal vasculature and may preserve renal function during indomethacin treatment. However, limited information exists on DA receptor-mediated signaling in the ductus and fenoldopam may prevent ductus closure given its vasodilatory nature. METHODS: DA receptor expression in CD-1 mouse vessels was analyzed by qPCR and immunohistochemistry. Concentration-response curves were established using pressure myography. Pretreatment with SCH23390 (DA1-like receptor antagonist), phentolamine (α -adrenergic receptor antagonist) or indomethacin addressed mechanisms for DA-induced changes. Fenoldopam's effects on postnatal ductus closure were evaluated in vivo. RESULTS: DA1 receptors were expressed equally in ductus and aorta. High-dose DA induced modest vasoconstriction under newborn O2 conditions. Phentolamine inhibited DA-induced constriction, while SCH23390 augmented constriction, consistent with a vasodilatory role for DA1 receptors. Despite this, fenoldopam had little effect on ductus tone nor indomethacin- or O2-induced constriction and did not impair postnatal closure in vivo. CONCLUSION(S): DA receptors are present in the ductus but have limited physiologic effects. DA-induced ductus vasoconstriction is mediated via α-adrenergic pathways. The absence of DA1-mediated impairment of ductus closure supports the study of potential role for fenoldopam during PDA treatment.

Rationale for Using Irreversible Epidermal Growth Factor Receptor Inhibitors in Combination with Phosphatidylinositol 3-Kinase Inhibitors for Advanced Head and Neck Squamous Cell Carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is a common and debilitating form of cancer characterized by poor patient outcomes and low survival rates. In HNSCC, genetic aberrations in phosphatidylinositol 3-kinase (PI3K) and epidermal growth factor receptor (EGFR) pathway genes are common, and small molecules targeting these pathways have shown modest effects as monotherapies in patients. Whereas emerging preclinical data support the combined use of PI3K and EGFR inhibitors in HNSCC, in-human studies have displayed limited clinical success so far. Here, we examined the responses of a large panel of patient-derived HNSCC cell lines to various combinations of PI3K and EGFR inhibitors, including EGFR agents with varying specificity and mechanistic characteristics. We confirmed the efficacy of PI3K and EGFR combination therapies, observing synergy with α isoform-selective PI3K inhibitor HS-173 and irreversible EGFR/ERBB2 dual inhibitor afatinib in most models tested. Surprisingly, however, our results demonstrated only modest improvement in response to HS-173 with reversible EGFR inhibitor gefitinib. This difference in efficacy was not explained by differences in ERBB target selectivity between afatinib and gefitinib; despite effectively disrupting ERBB2 phosphorylation, the addition of ERBB2 inhibitor CP-724714 failed to enhance the effect of HS-173 gefitinib dual therapy. Accordingly, although irreversible ERBB inhibitors showed strong synergistic activity with HS-173 in our models, none of the reversible ERBB inhibitors were synergistic in our study. Therefore, our results suggest that the ERBB inhibitor mechanism of action may be critical for enhanced synergy with PI3K inhibitors in HNSCC patients and motivate further preclinical studies for ERBB and PI3K combination therapies.